A system and method are disclosed for management of motor driven pumps. Specifically, the techniques are disclosed for efficient operation of a plurality of motor driven pumps powered by one or more prime movers.
Hydraulic fracturing is used to generate production from un-conventional oil and gas wells. The technique includes pumping of fluid into a wellbore at high pressure. Inside the wellbore, the fluid is forced into the formation. Pressurized fluid entering into the formation creates fissures releasing the oil or gas. The fluid such as water or gas together with solid proppants is introduced into the fissures to sustain the release of oil or gas from the formation. The pumping is performed using boost and fracturing pumps which are powered by large diesel generators. More than one pump may be operating in an oil well and one or more diesel generator may be used to provide power to these multiple pumps.
Electric motor driven pumps such as fracturing pumps are used to generate required wellhead pressure. A conventional system in the oil and gas industry employs a variable speed drive (VSD) that is fed by a fixed frequency AC supply to drive a single fracturing pump. Conventional techniques require a dedicated diesel engine and a dedicated VSD for each fracturing pump. A typical application may include about 16 pumps dedicated to one well head for fracking.
The excessive volumes of diesel fuel for pumping operation necessitates constant transportation of diesel tankers to the site and results in significant carbon dioxide emissions. Attempts to decrease fuel consumption and emissions by running large pump engines on “Bi-Fuel”, blending natural gas and diesel fuel together, have met with limited success. The dispatching of a plurality of prime movers for providing a required pressure profile may not be optimum. Thus, load balancing depends on the availability or non-availability of prime movers and one or more pumps. The operation of the plurality of pumps for each well head also may not be efficient in terms of fuel consumption. During the pumping operation, possibility of failure of one or more pumps necessitates unscheduled maintenance.
Various opportunities exist to minimize the run time of the prime movers and to optimize other aspects of the operation of the prime movers. There exists a need to proactively determine the fault conditions and determine performance of individual motor driven pumps of a fracking system for planned maintenance and protection of the motor driven pumps. Further, improved techniques for management of a plurality of motor driven pumps powered by a plurality of prime mover driven generators are desirable.